A new Scaphander species from the deep sea of Argentina

Abstract

Scaphander Montfort, 1810 is a genus of deep-sea soft-bottom gastropods composed of approximately 18 species distributed worldwide. Eilertsen and Malaquias (2013) revised the systematics of the genus in the Atlantic, and recognized eight valid species. The present study describes a new Scaphander species from novel samples obtained from the abyssal plains off Argentina, using morphological and molecular data. Shells, gizzard plates, radulae, and male reproductive systems were studied by optical and scanning electron microscopy, and compared with data from all other known Scaphander species. Bayesian molecular phylogenetics based on two mitochondrial (cythocrome c oxidase sub-unit I and 16S rRNA) and one nuclear (28S rRNA) genes together with the molecular species delimitation method Automatic Barcode Gap Discovery were used to compare the novel samples with all known Atlantic species. Our results revealed that the Argentian specimens have a distinct shell and penial papilla and molecularly were 13.1–13.9% distinct (COI uncorrected p-distance) from their closest relative, the northern amphi-Atlantic species Scaphander punctostriatus.